1. Technical Field
This application relates to a surgical apparatus, and more particularly, to a surgical buttress for use with a surgical stapling apparatus during operation of the stapling apparatus to apply a plurality of surgical fasteners to body tissue.
2. Background of Related Art
As medical and hospital costs continue to increase, surgeons are constantly striving to develop advanced surgical techniques. Advances in the surgical field are often related to the development of operative techniques which involve less invasive surgical procedures and reduce overall patient trauma. In this manner, the length of hospital stays can be significantly reduced, and, therefore, the hospital and medical costs can be reduced as well.
Although the present disclosure includes, but is not limited to use with endoscopic surgery, endoscopic surgery is one of the truly great advances in recent years to reduce the invasiveness of surgical procedures. Generally, endoscopic surgery involves incising through body walls for example, viewing and/or operating on the ovaries, uterus, gall bladder, bowels, kidneys, appendix, etc. There are many common endoscopic surgical procedures, including arthroscopy, laparoscopy (pelviscopy), gastroentroscopy and laryngobronchoscopy, just to name a few. Typically, trocars are utilized for creating the incisions through which the endoscopic surgery is performed. Trocar tubes or cannula devices are extended into and left in place in the abdominal wall to provide access for endoscopic surgical tools. A camera or endoscope is inserted through a relatively large diameter trocar tube which is generally located at the naval incision, and permits the visual inspection and magnification of the body cavity. The surgeon can then perform diagnostic and therapeutic procedures at the surgical site with the aid of specialized instrumentation, such as, forceps, cutters, applicators, and the like which are designed to fit through additional cannulas. Thus, instead of a large incision (typically 12 inches or larger) that cuts through major muscles, patients undergoing endoscopic surgery receive more cosmetically appealing incisions, between 5 and 10 millimeters in size. Recovery is, therefore, much quicker and patients require less anesthesia than traditional surgery. In addition, because the surgical field is greatly magnified, surgeons are better able to dissect blood vessels and control blood loss. Heat and water loss are greatly reduced as a result of the smaller incisions. In order to address the specific needs of endoscopic and/or laparoscopic surgical procedures, endoscopic surgical stapling devices have been developed and are disclosed in, for example, U.S. Pat. Nos. 5,040,715 (Green, et al.); 5,307,976 (Olson, et al.); 5,312,023 (Green, et al.); 5,318,221 (Green, et al.); 5,326,013 (Green, et al.); and 5,332,142 (Robinson, et al.).
In many surgical procedures, including those involved in open and endoscopic surgery, it is often necessary to staple tissue. It is especially challenging during endoscopic surgery because of the small openings through which the stapling of tissues must be accomplished. Instruments for this purpose can include two elongated members which are respectively used to capture or clamp tissue. Surgical devices wherein tissue is first grasped or clamped between opposing jaw structure and then joined by surgical fasteners are well known in the art. Typically, one of the members carries a fastener cartridge which houses a plurality of staples arranged in at least two lateral rows while the other member has an anvil that defines a surface for forming the staple legs as the staples are driven from the staple cartridge. The fasteners are typically in the form of surgical staples but two part polymeric fasteners can also be utilized. Generally, the stapling operation is effected by cam bars or wedges that travel longitudinally through the staple cartridge, with the cam bars acting upon staple pushers to sequentially eject the staples from the staple cartridge. A knife can travel between the staple rows to longitudinally cut and/or open the stapled tissue between the rows of staples. Such instruments are disclosed, for example, in U.S. Pat. No. 3,079,606 and U.S. Pat. No. 3,490,675.
A later stapler disclosed in U.S. Pat. No. 3,499,591 applies a double row of staples on each side of the incision. This is accomplished by providing a disposable loading unit in which a cam member moves through an elongate guide path between two sets of staggered staple carrying grooves. Staple drive members are located within the grooves and are positioned in such a manner so as to be contacted by the longitudinally moving cam member to effect ejection of the staples from the staple cartridge of the disposable loading unit. U.S. Surgical, the assignee of the present application, has manufactured and marketed endoscopic stapling instruments for several years. Examples of such instruments include the Multifire ENDO GIA* 30 and Multifire ENDO GIA* 60 instruments. Other examples of such staplers are disclosed in U.S. Pat. Nos. 4,429,695 and 5,065,929.
In staplers of the general type described above, it is conventional to provide separate anvil slots at each staple forming location. This makes it necessary to maintain relatively stringent alignment between the staple holding assembly and the anvil to assure that the staples enter the anvil slots correctly for proper clinching. The importance of maintaining good alignment between the relatively movable staple holding assembly and anvil assembly may contribute to the complexity of the instrument and to the cost of manufacturing and maintaining it. It is important that every staple be formed properly since an incompletely or improperly formed staple may leave a gap in a wound closure. Currently, surgical buttress material is also used in combination with these instruments as reinforcement to staple lines to further promote proper staple formation while reducing twisting/malformation caused by misalignment or unusual tissue while minimizing reliance on strict manufacturing tolerances. These instruments have provided significant clinical benefits. Nonetheless, improvements are possible, for example, by reducing the complexity of manufacture and/or application.